Canopy hard to close

[TASEsq]

Just got my canopy onto the aircraft for the first time, and I’m surprised at how much force there is on the canopy latch pins when closing.

You can see how much the canopy needs to get pulled down by the pins to close. I’m not sure it’s the canopy glass contacting the roll bar or not. Was thinking if the glass contacted first maybe it’s holding the frame up a little. I can loosen all the canopy attach screws to test this theory, but wanted to see how other people’s canopy fit first.

Side to side it seems to be aligned ok.

The photo is looking down the right canopy pin hole, with the canopy closed and sitting. It’s off by maybe 1/8”.

Here’s a video of how the canopy moved when being latched.

 

[BravoAlphaRomeo]

Trent, mine is also pretty tight. I really need to be pulling down on the upper handle a little bit to get the pins engaged. I figure this will only loosen over time so I wasn’t really planning on taking any steps to loosen it. If anything I considered putting a little bit more of a taper to the pins to let them slide in easier…

 

[PilotjohnS]

My canopy is hard to open, but i hate to work and loosen it up because if it gets too loose, i am no sure how i would tighten it up.

Interested in ideas here maybe i would work on it during my winter conditional inspection. Please post ideas here!

 

[HAL Pilot]

check for contact of the plexi on the roll bar frame just behind the handle top dead center. if its happening see page 38-14 on the wiki. I will DM you my observations

 

[TASEsq]

My canopy is hard to open, but i hate to work and loosen it up because if it gets too loose, i am no sure how i would tighten it up.

Interested in ideas here maybe i would work on it during my winter conditional inspection. Please post ideas here!

Thank you.

I’ve read that one, I think my frame was ok.

 

[Jetmart]

Do you have the weather stripping seals on yet? They will certainly loosen up over time.

 

[TASEsq]

Do you have the weather stripping seals on yet? They will certainly loosen up over time.

Yep - all the seals installed.

 

[MED]

Just got my canopy onto the aircraft for the first time, and I’m surprised at how much force there is on the canopy latch pins when closing.

You can see how much the canopy needs to get pulled down by the pins to close. I’m not sure it’s the canopy glass contacting the roll bar or not. Was thinking if the glass contacted first maybe it’s holding the frame up a little. I can loosen all the canopy attach screws to test this theory, but wanted to see how other people’s canopy fit first.

Side to side it seems to be aligned ok.

The photo is looking down the right canopy pin hole, with the canopy closed and sitting. It’s off by maybe 1/8”.

Here’s a video of how the canopy moved when being latched.

Is it possible there is too much sealant along the forward seal at the rear of the cowling? I had to remove a large portion of it, making sure it is still sealed from rain, but not keeping the canopy from closing. Remember, you will want to be able to close the canopy from outside, too.

 

[Nova RV]

How did it operate before putting on the seals? Mine never had that misalignment and has always been smooth and relatively easy to actuate.

 

[Jetmart]

Yep - all the seals installed.

When I first started closing my canopy I had to pull down hard on the overhead handle while operating the pin locking mechanism. This was a concern especially when closing from the outside. Had to push down in the centre on the outside to both close it and open it. It has loosened up a fair bit over the last 250 hours but still requires a slight pull from the centre when closing. Nothing seems to be out of alignment. It is strictly sitting on the foam seals that get gets compressed. I figure it is better slightly tight than too loose of a fit. My pins lined up perfectly without the foam seals on it.

 

[TASEsq]

Thanks for those ideas.

I don’t have the forward sealant done yet - the forward skin is just cleco’d on.

I never tried closing it without the aft seal installed. I did all the work on the bench, including the seals, then put the canopy on the airframe. The aft seal would be easy to remove and check.

When it’s closed and latched I can’t get a piece of paper to slide in between the canopy and the roll bar. I suspect this is the issue.

I asked another question before I drilled as it seemed to me the canopy bow was a little low compared to the roll bar - but then when I drilled and cleco’d the canopy on, the gaps went away. So I thought it was all good. I suspect that now I’ve tightened the screws, it’s pulled the canopy down to the canopy bow, and now it’s hitting the roll bar before it the canopy frame moves down to the proper position where it was when I drilled.

Canopy frame versus roll bar.

Is this a normal fit of the canopy frame to the roll bar? In the attached photos, the canopy frame is the white tape and the roll bar is the blue tape. On the sides the canopy frame is a fair bit wider than the roll bar, but at the top the canopy frame is shorter than the roll bar. To the...

vansairforce.net

I appreciate all the insight - specifically this might not be normal. Tomorrow I will loosen off the screws and see what it’s like. If still tight, will pull out the aft seal and check again. If I need to shim up the centre of the canopy, I’ll get some nylon washers, then once the thickness is worked out, make up a shim strip (as recommended by vans).

 

[Ron B.]

Just as a data point , once my canopy is on the vent position blocks ( canopy resting about 3” from sil) all I have to do is move the pins enough for the canopy to drop smoothly closed and then latch the canopy closed. All seals are in . No requirement to pull down at all.
I’ve also worked on another 14 and had trouble determining why I couldn’t get the canopy to close properly. Turns out the door sil somehow didn’t get put together straight. There is a bow in it. It did close properly until I installed the missing seal. The seal was binding and requiring a fair amount of pulling down on the handle.

 

[TASEsq]

A bit of a follow up for those playing at home.

I added strips of paper along the top of the canopy and marked the areas where the canopy was pushing against the roll bar.

I loosened off the screws along the aft canopy, and it was noticeably easier to close. I then removed the aft seal, but this didn’t really change much.

I added some NAS1515H08 washers (1/16 thick nylon) at the screw locations where the paper didn’t slide out. The nuts were retightened.

The canopy is still slightly misaligned, probably due to the forward seals, and pulls down slightly as the pins go in - but is much easier than before to close. I definitely think the canopy was touching the roll bar, before the canopy frame had seated to the correct location - due to the earlier identified issue of the canopy frame being lower than the roll bar.

If I were doing this again, I would have added washers to the canopy frame before drilling, to make sure the canopy glass was not sitting hard on the roll bar (using paper to check).

I also polished up the stainless pins and plates and got them attached, finally finishing chapter 38 (for now anyway - still a have the forward skin to rivet in, and therefore the canopy clips)

Thanks to all who rendered assistance.